Fluid delivery methods and systems are highly desirable for irrigation, filtration, fluid supply, fluid recharging and other fluid delivery purposes. The ability to deliver proper amounts of fluid to plants, chambers, compartments or other devices in a constant and controlled manner is particularly important for maintaining constant plant growth or supplying liquid to devices that require fluid to function properly. Fluids in general need to move from one place to another in nature as well as in innumerous technological processes. Fluids may be required in places where the availability of fluid is not expected (i.e., supply). Fluids may also be undesired in places where the fluid is already in place (i.e., drainage). Maintaining the fluid cycling dynamically permits the transference of substances in solutions moving from place to place, such as the internal functioning of multi-cellular organisms. The process of moving fluid as unsaturated flow also offers important features associated with characteristics, including the complex hydrodynamic interaction of fluid in the liquid phase in association with the spatially delineated porosity of the solid phase.
Fluid movement is also required to move substances in or out of solutions or which may be suspended in a flow. Bulk movement of fluids has been performed efficiently for centuries inside tubular cylindrical objects, such as pipes. Often, however, fluids are required to be delivered in very small amounts at steady ratios with a high degree of control governed by an associated fluid or liquid matric potential. Self-sustaining capabilities controlled by demand are also desired in fluid delivery systems, along with the ability to maintain ratios of displacement with the porosity of solid and air phases for efficient use. Field irrigation has not yet attained such advancement because the soil is not connected internally to the hose by any special porous interface. This particular need can be observed within plants and animals in biological systems, in the containerized plant industry, printing technology, writing tools technology, agricultural applications (i.e., irrigation/drainage), fluid-filtering, biotechnology-like ion-exchange chromatography, the chemical industries, and so forth.
A fluid that possesses a positive pressure can be generally defined in the field of hydrology as saturated fluid. Likewise, a fluid that has a negative pressure (i.e., or suction) can be generally defined as an unsaturated fluid. Fluid matric potential can be negative or positive. For example, water standing freely at an open lake, can be said to stand under a gravity pull. The top surface of the liquid of such water accounts for zero pressure known as the water table or hydraulic head. Below the water table, the water matric potential (pressure) is generally positive because the weight of the water increases according to parameters of force per unit of area. When water rises through a capillary tube or any other porosity, the water matric potential (e.g., conventionally negative pressure or suction) is negative because the solid phase attracts the water upward relieving part of its gravitational pull to the bearing weight. The suction power comes from the amount of attraction in the solid phase per unit of volume in the porosity.
A tube is a perfect geometrical figure to move bulk fluids from one place to another. For unsaturated flow, however, a tube is restricted because it will not permit lateral flow of fluid in the tube walls leading to anisotropic unsaturated flow with a unique longitudinal direction. Tube geometry is very important when considering applications of fluid delivery and control involving saturated conditions, such as, for example in pipes. The wall impermeability associated with tube geometry thus becomes an important factor in preventing fluid loss and withstanding a high range of pressure variation. In such a situation, fluids can move safely in or out only through associated dead ends of an empty tube or cylinder.
Random irregular porous systems utilized for unsaturated flow employ general principles of capillary action, which require that the tube geometry fit properly to the porosity, which is generally analogous to dimensions associated between capillary tubes and the voids in the random porosity. Random porosity has an irregular shape and a highly variable continuity in the geometrical format of the void space, which does not fit to the cylindrical spatial geometry of capillary tubes. This misunderstanding still holds true due to the fact that both capillary tubes and porosity voids are affected by the size of pores to retain and move fluids as unsaturated conditions. Consequently, an enhanced porosity for unsaturated flow that deals more clearly with the spatial geometry is required. This enhanced porosity becomes highly relevant when moving fluids between different locations by unsaturated conditions if reliability is required in the flow and control of fluid dynamic properties.
When fluids move as unsaturated flow, they are generally affected by the porosity geometry, which reduces the internal cohesion of the fluid, thereby making the fluid move in response to a gradient of solid attraction affecting the fluid matric potential. Continuity pattern is an important factor to develop reliability in unsaturated flow. Continuous parallel solid tube-like structures offer this feature of regular continuity, thereby preventing dead ends or stagnant regions common to the random microporosity. The system becomes even more complex because the fluid-holding capacity of the porosity has a connective effect of inner fluid adhesion-cohesion, pulling the molecules down or up. Using common cords braided with solid cylinders of synthetic fibers, a maximum capillary rise of near two feet has been registered.
Specialized scientific literature about unsaturated zones also recognizes this shortcoming. “Several differences and complications must be considered. One complication is that concepts of unsaturated flow are not as fully developed as those for saturated flow, nor are they as easily applied.” (See Dominico & Schwartz, 1990. Physical and Chemical Hydrogeology. Pg. 88. Wiley) Concepts of unsaturated flow have not been fully developed to date, because the “capillary action” utilized to measure the adhesion-cohesion force of porosity is restrained by capillary tube geometry conceptions. The term “capillary action” has been wrongly utilized in the art as a synonym for unsaturated flow, which results in an insinuation that the tube geometry conception captures this phenomenon when in truth, it does not.
A one-way upward capillary conductor was disclosed in a Brazilian patent application, Artificial System to Grow Plants, BR P1980367, on Apr. 4, 1998 to the present inventor. The configuration disclosed in BR P1980367 is limited, because it only permits liquid to flow upward from saturated to unsaturated zones utilizing a capillary device, which implies a type of tubular structure. The capillary conductor claimed in the Brazilian patent application has been found to contain faulty functioning by suggesting the use of an external constriction layer and an internal longitudinal flow layer. Two layers in the conductor have led to malfunctioning by bringing together multiple differential unsaturated porous media, which thereby highly impairs flow connectivity.
Unsaturated flow is extremely dependent on porosity continuity. All devices using more than one porous physical structure media for movement of unsaturated fluid flow are highly prone to malfunctioning because of the potential for microscopic cracks or interruptions in the unsaturated flow of fluid in the media boundaries. Experimental observations have demonstrated that even if the flow is not interrupted totally, the transmittance reduction becomes evident during a long period of observation.
The appropriate dimensions and functioning of porosity can be observed in biological unsaturated systems because of their evolutionary development. Internal structures of up to 100 :m in cross-sectional diameter, such as are present, for example, in the phloem and xylem vessels of plants are reliable references. But, interstitial flow between cells function under a 10 :m diameter scale. It is important to note that nature developed appropriate patterns of biological unsaturated flow porosity according to a required flow velocity, which varies according to a particular organism. These principals of unsaturated flow are evidenced in the evolution and development of plants and animals dating back 400 millions years, and particularly in the early development of multi-cellular organisms. These natural fluid flow principles are important to the movement of fluids internally and over long upward distances that rely on the adhesion-cohesion of water, such as can be found in giant trees or in bulk flow as in vessels. Live beings, for example, require fluid movement to and from internal organs and tissues for safe and proper body functioning.
Plants mastered unsaturated flow initially in their need to grow and expand their bodies far beyond the top surface in search of sunlight and to keep their roots in the ground for nutrients and water absorption. Plants learned to build their biological porosity block by block through molecular controlled growth. Plants can thus transport fluid due to their own adhesion-cohesion and to the special solid porosity of the associated tissues, providing void for flow movement and solid structure for physical support. Plants not only developed the specially organized porosity, but also the necessary fluid control based on hydrophilic and hydrophobic properties of organic compounds in order to attract or repel water, internally and externally according to metabolic specific requirements. Plants learned to build their biological porosity controlling the attraction in the solid phase by the chemistry properties of organic compounds as well as their arrangement in an enhanced spatial geometry with appropriate formats for each required unsaturated flow movement pattern.
The one-way capillary conductor disclosed by Silva in Brazilian patent application BR P1980367 fails to perform unsaturated siphoning due to tubing theory and a one-way upward flow arrangement. A tube is not an appropriate geometrical containing figure for unsaturated flow because it allows fluids to move in and out only by the ends of the hollow cylindrical structure. A one-way directional flow in a pipe where the fluid has to pass through the ends of the pipe is highly prone to malfunctioning due to clogging, because any suspended particles in the flow may block the entrance when such particles is larger than the entrance. Unsaturated flow requires multidirectional flow possibilities, as well as a special spatial geometry of the porosity to provide continuity. Unsaturated flow in a conductor cannot possess walls about the tube for containment. According to Webster's Dictionary, the term capillary was first coined in the 15th century, describing a configuration having a very small bore (i.e., capillary tube). Capillary attraction (1830) was defined as the force of adhesion and cohesion between solid and liquid in capillarity. Consequently, a geometric tube having a small structure can only function one-way upward or downward without any possibility of lateral flow. Capillary action operating in a downward direction can lose properties of unsaturated flow because of a saturated siphoning effect, which results from the sealing walls.
The complexity of unsaturated flow is high, as the specialized literature has acknowledged. For example, the inner characteristics between saturated flow and unsaturated flows are enormous and critical to develop reliability for unsaturated flow applications. Interruption of continuity on pipe walls of saturated flow leads to leaking and reduced flow velocity. In the case of unsaturated flow interruption in the continuity can be fatal halting completely the flux. This can occur because the unsaturated flow is dependent on the continuity in the solid phase, which provides adhesion-cohesion connectivity to the flowing molecules. Leaking offers an easy detection feature to impaired saturated flow, but cracking is neither perceptible nor easy to receive remedial measures in time to rescue the unsaturated flow functioning imposed by the sealing walls.
The efficiency of unsaturated flow is highly dependent on porosity continuity and the intensity ratio of attraction by unit of volume. A simple water droplet hanging from a horizontal flat surface having approximately 4 mm of height, for example, can have vertical chains of water molecules of approximately 12 million molecules linked to one other by hydrogen bonding and firmly attached to the solid material that holds it. Water in a hanging droplet has a ratio of 1:0.75 holding surface to volume. If this water were stretched vertically into a tube of 10:m of diameter, the water column can reach 213 m high. The relation of surface to volume can increase to more than five hundred times, explaining the high level of attraction in the porosity to move fluids by the reduction of their bearing weight and consequent increase of dragging power of porosity. If the diameter were only 5 :m, the water column can reach 853 m for this simple water droplet.
The amount of attraction in the porosity by volume is dependent on the shape format of the solid surface as well as its stable spatial continuity. The rounding surfaces are generally the best ones to concentrate solid attraction around a small volume of fluid. Cubes offer the highest level of surface by volume, but such cubes neither provide a safe void for porosity nor rounding surfaces. A sphere offers a high unit of surface by volume. Sphere volume can occupy near 50% of the equivalent cube. Granular soil structure usually has approximately 50% of voids associated with the texture of soil aggregates. A void in the granular porous structure offers low reliability for continuity because the granules cannot be attached safely to each other and the geometry of the void randomly misses an ensured connectivity. Cells are granule-like structures in the tissues of life-beings that learned to attach to each other in a precise manner pin order to solve such a dilemma.
Larger spherical particles can potentially offer much more surface area than cylindrical particles, because the surface area of spheres increases according to the cubic power of the radius, while the cylinders increase to multiples of the radius without considering the circle area. On the other hand, smaller and smaller geometrical formats lead to more reduction of the surface of spherical formats than cylindrical formats. Cylinders also maintain a regular longitudinal shape pattern because it can be stretched to any length aimed in industrial production. A bundle of cylinders changing size have a preserved void ratio and an inverse relation of solid attraction to volume bearing weight in the porosity.
The present inventor has thus concluded that the dynamics between saturated and unsaturated conditions as expressed in the fluid matric potential can be utilized to harness the unsaturated flow of fluid using the macrostructure of reversible unsaturated siphons for a variety of purposes, such as irrigation and drainage, fluid recharging and filtration, to name a few. The present inventor has thus designed unique methods and systems to recover or prevent interruption in liquid unsaturated flow in both multidirectional and reversible direction by taking advantage of the intrinsic relationship between unsaturated and saturated hydrological zones handling a vertical fluid matric gradient when working under gravity conditions. The present inventor has thus designed an enhanced microporosity called tubarc, which is a tube like geometric figure having continuous lateral flow in all longitudinal extension. The tubarc porosity disclosed herein with respect to particular embodiments can offer a high level of safe interconnected longitudinally, while providing high anisotropy for fluid movement and reliability for general hydrodynamic applications.